More particularly, the invention relates to an annular combustion chamber for a turbomachine of the type comprising an inner wall, an outer wall, and a chamber end wall disposed between said inner and outer walls in the upstream region of said chamber, the chamber end wall presenting an outer fastener rim and/or an inner fastener rim, and the outer and/or inner wall presenting an upstream fastener rim, the chamber end wall and the outer and/or inner wall being fastened together via their fastener rims.
A portion of a turbojet including a prior art combustion chamber of the above-specified type is shown in FIG. 1.
That combustion chamber 24 comprises an inner wall 26, an outer wall 28, and a chamber end wall 30 disposed between said inner and outer walls, in the upstream region of said chamber. The inner and outer walls 26 and 28 are circular and coaxial about an axis 10, which axis is the axis of rotation of the turbojet.
Upstream and downstream are defined relative to the normal flow direction of gas through the turbojet.
The chamber end wall 30 presents at its inner and outer peripheries, respectively: an inner fastener rim 32 and an outer fastener rim 34. Furthermore, at their upstream ends, the inner and outer walls 26 and 28 present respective fastener rims 36 and 38. The chamber end wall 30 and the outer wall 28 (or inner wall 26) are fastened together via the rims 34 and 38 (or the rims 32 and 36) by means of bolts.
The air flow F coming from the compressor of the turbojet (not shown) that is situated upstream from the combustion chamber 24 is represented by arrows F in FIG. 1.
The outer wall portion 28a (or inner wall portion 26a) situated immediately downstream from the chamber end wall 30 is subjected to very high temperatures in operation, and it is necessary to cool this wall portion 28a as effectively as possible.
To perform such cooling, it is known to make multiple small-sized perforations in this wall portion 28a (or 26a) referred to as multiperforations 55 (where the size of these multiperforations is deliberately exaggerated in the figures).
The multiperforations 55 are fed with air by the air flow F passing around the chamber 24 so as to create a protective air film f on the inside face (i.e. the face facing towards the inside of the chamber 24) of the wall portion 28a (or 26a). This air film is represented by arrows f in FIG. 1.